The disclosure of Japanese Patent Application No. 2000-311243 filed on Oct. 11, 2000, including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of Invention
The invention relates to a vehicular control apparatus and a method for controlling a gear change which controls a gear change of an automatic transmission on the basis of information with respect to an inclination of a road surface where the vehicle is traveling and information with respect to a curve of the traveling road.
2. Description of Related Art
There have been proposed control apparatuses determining an inclination of a road surface on which a vehicle travels so as to select a gear change map corresponding to the inclination, determining on the basis of navigation information whether or not a mountainous road is a comparatively long ascending or descending slope road, and correcting an inclination parameter in the case where it is a comparatively long ascending or descending slope road so as to make it easy to switch to a gear change map corresponding to a large inclination. One of the examples is a control apparatus for controlling a gear shift of an automatic transmission described in Japanese Patent Laid-open Publication No. 2000-65201.
In this case, in the conventional control apparatus for controlling the gear change mentioned above, a determined inclination value is corrected on the basis of the inclination of the road surface, the gear change map is selected on the basis of a comparison between the determined inclination value and an actual inclination of the road surface, a gear change is determined on the basis of an actual vehicle speed and an accelerator opening degree in accordance with the gear change map, and a gear stage of an automatic transmission is switched such that a determined gear change is executed. Accordingly, in the conventional control apparatus for controlling the gear change described above, the gear stage corresponding to the curve of the road and the inclination of the road surface is not always selected. Therefore, there is a problem that the gear stage corresponding to the road condition can not be directly obtained.
The invention is made for the purpose of solving the above-mentioned problem, and an object of the invention is to provide a vehicular control apparatus for controlling a gear change in which a gear stage corresponding to a curve of a road and an inclination of a road surface can be directly obtained.
In order to achieve the object, there is provided a vehicular control apparatus for controlling an automatic gear change which executes a gear change control of an automatic transmission on the basis of information with respect to an inclination of a road surface where the vehicle is traveling, for example, executes a cooperative gear change control reflecting information with respect to the inclination of the road surface where the vehicle is traveling on the gear change of the automatic transmission, including a controller (a) detecting the inclination of the vehicle traveling road so as to output a road surface inclination information with respect to the inclination, (b) detecting a curve of the vehicle traveling road so as to output a curve information with respect to the curve, and (c) determining the gear change of the automatic transmission on the basis of actual curve information and road surface inclination information in accordance with a previously stored gear change map, and switching a gear stage such that a determined gear change is executed.
Further, in order to achieve the object, there is provided the following vehicular control method for controlling an automatic gear change.
That is, there is provided a vehicular control method for controlling an automatic gear change including steps of:
detecting an inclination of a vehicle traveling road;
detecting a curve degree of the vehicle traveling road;
determining a gear change of an automatic transmission on the basis of the road surface inclination and the curve degree in accordance with a previously stored gear change map; and
executing a switching such that a gear stage of the automatic transmission becomes a determined gear stage.
Thus, the gear change of the automatic transmission is directly determined on the basis of the actual curve information and road surface inclination information in accordance with the previously stored gear change map using the controller. In addition, the gear stage is switched such that the determined gear change is executed. Therefore, the gear stage or a gear ratio corresponding to the curve of the road or the inclination of the road surface can be instantly obtained.